sRGBfloat cTexture::BicubicInterpolation(double x, double y, const sRGB8 *bitmap, int w, int h) const
{
int ix = x;
int iy = y;
double rx = (x - ix);
double ry = (y - iy);
double R[4][4], G[4][4], B[4][4];
for(int yy = 0; yy < 4; yy++)
{
for(int xx = 0; xx < 4; xx++)
{
int ixx = ix + xx - 1;
int iyy = iy + yy - 1;
ixx = (ixx + w) % w;
iyy = (iyy + h) % h;
int addess2 = ixx + iyy * w;
sRGB8 pixel = bitmap[addess2];
R[xx][yy] = pixel.R;
G[xx][yy] = pixel.G;
B[xx][yy] = pixel.B;
}
}
double dR = bicubicInterpolate(R, rx, ry);
double dG = bicubicInterpolate(G, rx, ry);
double dB = bicubicInterpolate(B, rx, ry);
if(dR < 0) dR = 0; if(dR > 255) dR = 255;
if(dG < 0) dG = 0; if(dG > 255) dG = 255;
if(dB < 0) dB = 0; if(dB > 255) dB = 255;
return sRGBfloat(dR/256.0, dG/256.0, dB/256.0);
}
// src is a grid src_rows * src_cols
// dest is a pre-allocated grid, dest_rows*dest_cols
void interpolate_image(float *src, uint8_t src_rows, uint8_t src_cols,
float *dest, uint8_t dest_rows, uint8_t dest_cols) {
float mu_x = (src_cols - 1.0) / (dest_cols - 1.0);
float mu_y = (src_rows - 1.0) / (dest_rows - 1.0);
float adj_2d[16]; // matrix for storing adjacents
for (uint8_t y_idx=0; y_idx < dest_rows; y_idx++) {
for (uint8_t x_idx=0; x_idx < dest_cols; x_idx++) {
float x = x_idx * mu_x;
float y = y_idx * mu_y;
//Serial.print("("); Serial.print(y_idx); Serial.print(", "); Serial.print(x_idx); Serial.print(") = ");
//Serial.print("("); Serial.print(y); Serial.print(", "); Serial.print(x); Serial.print(") = ");
get_adjacents_2d(src, adj_2d, src_rows, src_cols, x, y);
/*
Serial.print("[");
for (uint8_t i=0; i<16; i++) {
Serial.print(adj_2d[i]); Serial.print(", ");
}
Serial.println("]");
*/
float frac_x = x - (int)x; // we only need the ~delta~ between the points
float frac_y = y - (int)y; // we only need the ~delta~ between the points
float out = bicubicInterpolate(adj_2d, frac_x, frac_y);
//Serial.print("\tInterp: "); Serial.println(out);
set_point(dest, dest_rows, dest_cols, x_idx, y_idx, out);
}
}
}
// ray方向からの放射輝度を求める
Color radiance(const Ray &ray, const int depth, bool interpolation = true) {
double t; // レイからシーンの交差位置までの距離
int id; // 交差したシーン内オブジェクトのID
Vec normal; // 交差位置の法線
if (!intersect_scene(ray, &t, &id, &normal))
return BackgroundColor;
const Rectangle &obj = recs[id];
const Vec hitpoint = ray.org + t * ray.dir; // 交差位置
// シーンを構成するジオメトリは全て完全拡散面と仮定
switch (DIFFUSE) {
case DIFFUSE: {
const Vec v = hitpoint - obj.p0;
const double a_len = Dot(v, Normalize(obj.a));
const double b_len = Dot(v, Normalize(obj.b));
double da = obj.a_num * a_len / obj.a_len;
double db = obj.b_num * b_len / obj.b_len;
int ia = int(da); if (ia >= obj.a_num) ia --;
int ib = int(db); if (ib >= obj.b_num) ib --;
// バイキュービック補間
if (interpolation) {
Color c[4][4];
int ia = int(da - 0.5);
int ib = int(db - 0.5);
for (int i = 0; i < 4; i ++) {
for (int j = 0; j < 4; j ++) {
c[i][j] = obj.sample(ia + i - 1, ib + j - 1);
}
}
int ia0 = int(da - 0.5);
int ib0 = int(db - 0.5);
double dx = da - ia0 - 0.5;
double dy = db - ib0 - 0.5;
if (dx < 0.0) dx = 0.0;
if (dx >= 1.0) dx = 1.0;
if (dy < 0.0) dy = 0.0;
if (dy >= 1.0) dy = 1.0;
return PI * bicubicInterpolate(c, dx, dy);
}
// 完全拡散面なのでPI倍
return PI * obj.patch[ia * obj.b_num + ib];
} break;
}
}
bool ofPixels_<PixelType>::resizeTo(ofPixels_<PixelType>& dst, ofInterpolationMethod interpMethod) const{
if(&dst == this){
return true;
}
if (!(isAllocated()) || !(dst.isAllocated()) || getBytesPerPixel() != dst.getBytesPerPixel()) return false;
int srcWidth = getWidth();
int srcHeight = getHeight();
int dstWidth = dst.getWidth();
int dstHeight = dst.getHeight();
int bytesPerPixel = getBytesPerPixel();
PixelType * dstPixels = dst.getData();
switch (interpMethod){
//----------------------------------------
case OF_INTERPOLATE_NEAREST_NEIGHBOR:{
int dstIndex = 0;
float srcxFactor = (float)srcWidth/dstWidth;
float srcyFactor = (float)srcHeight/dstHeight;
float srcy = 0.5;
for (int dsty=0; dsty<dstHeight; dsty++){
float srcx = 0.5;
int srcIndex = int(srcy)*srcWidth;
for (int dstx=0; dstx<dstWidth; dstx++){
int pixelIndex = int(srcIndex + srcx) * bytesPerPixel;
for (int k=0; k<bytesPerPixel; k++){
dstPixels[dstIndex] = pixels[pixelIndex];
dstIndex++;
pixelIndex++;
}
srcx+=srcxFactor;
}
srcy+=srcyFactor;
}
}break;
//----------------------------------------
case OF_INTERPOLATE_BILINEAR:
// not implemented yet
ofLogError("ofPixels") << "resizeTo(): bilinear resize not implemented, not resizing";
break;
//----------------------------------------
case OF_INTERPOLATE_BICUBIC:
float px1, py1;
float px2, py2;
float px3, py3;
float srcColor = 0;
float interpCol;
int patchRow;
int patchIndex;
float patch[16];
int srcRowBytes = srcWidth*bytesPerPixel;
int loIndex = (srcRowBytes)+1;
int hiIndex = (srcWidth*srcHeight*bytesPerPixel)-(srcRowBytes)-1;
for (int dsty=0; dsty<dstHeight; dsty++){
for (int dstx=0; dstx<dstWidth; dstx++){
int dstIndex0 = (dsty*dstWidth + dstx) * bytesPerPixel;
float srcxf = srcWidth * (float)dstx/(float)dstWidth;
float srcyf = srcHeight * (float)dsty/(float)dstHeight;
int srcx = (int) MIN(srcWidth-1, srcxf);
int srcy = (int) MIN(srcHeight-1, srcyf);
int srcIndex0 = (srcy*srcWidth + srcx) * bytesPerPixel;
px1 = srcxf - srcx;
py1 = srcyf - srcy;
px2 = px1 * px1;
px3 = px2 * px1;
py2 = py1 * py1;
py3 = py2 * py1;
for (int k=0; k<bytesPerPixel; k++){
int dstIndex = dstIndex0+k;
int srcIndex = srcIndex0+k;
for (int dy=0; dy<4; dy++) {
patchRow = srcIndex + ((dy-1)*srcRowBytes);
for (int dx=0; dx<4; dx++) {
patchIndex = patchRow + (dx-1)*bytesPerPixel;
if ((patchIndex >= loIndex) && (patchIndex < hiIndex)) {
srcColor = pixels[patchIndex];
}
patch[dx*4 + dy] = srcColor;
}
}
interpCol = (PixelType)bicubicInterpolate(patch, px1,py1, px2,py2, px3,py3);
dstPixels[dstIndex] = interpCol;
}
}
}
break;
}
return true;
}
//bool newQuad = false;
/// \brief Interpolate the value for point \a x, \a y from the values at the four corners of \a quad
double quadInterpolate(qQuadValue quad, double x, double y, bool useBicubic = true)
{
double w = quad.width();
double h = quad.height();
if(useBicubic)
{
// Use bicubic impl from http://www.paulinternet.nl/?page=bicubic
double unitX = (x - quad.left() ) / w;
double unitY = (y - quad.top() ) / h;
double c1 = quad.tl.value,
c2 = quad.tr.value,
c3 = quad.br.value,
c4 = quad.bl.value;
double p[4][4] =
{
// {c1,c1,c2,c2},
// {c1,c1,c2,c2},
// {c4,c4,c3,c3},
// {c4,c4,c3,c3}
// Note: X runs DOWN, values below are (x1,y1)->(x1,y4), NOT (x1,y1)->(x4,y1) as above (commented out)
{c1,c1,c4,c4},
{c1,c1,c4,c4},
{c2,c2,c3,c3},
{c2,c2,c3,c3}
};
double p2 = bicubicInterpolate(p, unitX, unitY);
//if(p2 > 1.0 || unitX > 1. || unitY > 1. || newQuad)
//if(newQuad && unitX > 0.99)
//{
//qDebug() << "bicubicInterpolate: unit:"<<unitX<<","<<unitY<<": p2:"<<p2<<", w:"<<w<<", h:"<<h<<", x:"<<x<<", y:"<<y<<", corners:"<<corners[0].point<<corners[1].point<<corners[2].point<<corners[3].point<<", v:"<<c1<<c2<<c3<<c4;
//newQuad = false;
//}
return p2;
}
else
{
// Very simple implementation of http://en.wikipedia.org/wiki/Bilinear_interpolation
double fr1 = (quad.br.point.x() - x) / w * quad.tl.value
+ (x - quad.tl.point.x()) / w * quad.tr.value;
double fr2 = (quad.br.point.x() - x) / w * quad.bl.value
+ (x - quad.tl.point.x()) / w * quad.br.value;
double h1 = (quad.br.point.y() - y),
h2 = (y - quad.tl.point.y());
double p1 = h1 / h * fr1
+ h2 / h * fr2;
//qDebug() << "quadInterpolate: "<<x<<" x "<<y<<": "<<p1<<" (h1:"<<h1<<", h2:"<<h2<<", fr1:"<<fr1<<",fr2:"<<fr2<<",w:"<<w<<",h:"<<h<<"), bry:"<<quad.br.point.y()<<", tly:"<<quad.tl.point.y();
return p1;
}
}